In medical practice, various tests and diagnoses are carried out by imaging an affected area included in an internal organ, skeleton, and the like using X-rays and the like. In recent years, a dynamic image in which the movement of the affected area is captured can be acquired relatively easily using the X-ray and the like due to the application of digital technique.
Since the dynamic image can be imaged with respect to a subject region including a target site using a semiconductor image sensor such as an FPD (Flat Panel Detector), diagnosis by movement analysis of the target site and the like, which cannot be performed in the still imaging and diagnosis by the conventional X-ray imaging, can be performed. For example, consideration for assisting (X-ray dynamic image CAD) the diagnosis/treatment is also being performed by extracting the ventilation information in the lung field from the chest X-ray dynamic image, and performing the quantitative analysis of the dynamic function from the change and movement in concentration in the lung field, and the like.
The determining method of the imaging start/end timing in performing the diagnosis includes an automatic imaging start/end timing determining method and a manual imaging start/end timing determination method.
As for the automatic imaging start/end timing determining method, there is Patent Document 1, for example. In the technique disclosed in Patent Document 1, a respiration cycle is detected by another device, and an imaging timing including at least one of an imaging start timing and an imaging end timing is automatically controlled according to the respiration cycle.
On the other hand, in the manual imaging start/end timing determining method, the desired timing is determined by the operation of the photographer.
In addition, Patent Document 2 discloses a technique of performing the imaging at low irradiation amount in a predetermined frame rate, detecting a change amount of an image between the frames, and setting a frame rate of the imaging at high irradiation amount based on the change amount.